SubZero Factor 1 Plus Base Layer Review – Long Sleeve Seamless Thermal Insulation

Last Updated on 25/03/2021

SubZero Factor 1 Plus Base Layer Review – Long Sleeve Seamless Thermal Insulation

SubZero Factor 1 Plus Base Layer Review

SubZero Factor 1 Plus Base Layer Review

This SubZero Factor 1 Plus Base Layer Review comes right as the cold weather is hitting countries across the globe and Autumn is well and truly upon England. The SubZero Factor 1+ is a lightweight synthetic base layer with seamless construction and a very comfortable finish. The material is stretchy to 100% which means it provides a close fit without feeling restrictive at all. Breathable enough to wear for a spectrum of activities and warm enough to wear as your base layer in frigid temperatures. Keep reading this Sub Zero Factor 1 Plus Base Layer Review for a breakdown of my thoughts or see below for the specs and features.


SubZero Factor 1 Base Layer Review
  • Sun protection factor: 50+
  • TOG: 0.47
  • Fabric: 100% Polyamide
  • Average weight: 200g
  • Fit: Unisex snug
  • Size availability: XSmall-XXLarge
  • Colours: Black, White, Red, Aqua, Fluorescent Yellow, Pink, Khaki, Lime Green, Purple, Navy, Blue
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SubZero Factor Base Layer
  • Made in England
  • No-chafe shoulder seams
  • Seamless body for extra comfort
  • Long body length
  • Set-in sleeves to maximise insulation and wicking
  • Stretch rib zones for support
  • Waffle zones for enhanced heat retention and wicking
  • Super soft construction
  • Quick drying


When I initially tried the SubZero Factor 1 Plus base layer on I was almost taken back by how soft and stretchy it was. Having gotten used to merino wool base layers, I wasn’t sure this top would have a place in my outdoor gear room. After wearing it for 3 days non stop since I got I can honestly say that it is one of the comfiest base layer tops that I now own. The super stretchy material, as well as well proportioned arms and torso, don’t restrict your movements in the slightest and the seamless construction creates a super smooth finish to prevent any rubbing or itchiness.


Fitting close to the skin for thermal efficiency but feeling like any normal long sleeve top, the SubZero Factor 1+ base layer has a very casual feel to it. The longer cut on both the arms and the torso means that you don’t have to tuck it into your pants if you don’t want to. As well as the longer cut, the hem on the body is made from a slightly less elasticated fabric which stops the shirt riding up underneath a backpack. I really like the way it feels underneath a t-shirt and even with the sleeves rolled up it doesn’t feel too tight at all.

Sub Zero Factor 1 Plus Base Layer Top Review


Having not tested it in temperature below freezing yet I can only go off what I have experienced over the last week, to which I am very impressed. The nights have been getting very cold during this SubZero Factor 1+ base layer review and the difference between wearing the top not wearing it is quite drastic in terms of warmth felt. It is by no means the warmest base layer I have ever worn but it is not designed to be. It is much more of an active outdoors base layer that you specifically won’t overheat in or can wear every day under a t-shirt. I have always been a fan of base layers having skied and snowboarded from an early age and this top offers all the warmth you could need from an everyday base layer.


The breathability of the SubZero Factor 1+ base layer is very good and has a super efficient hydrophilic finish to wick perspiration away from your body. The problem with some heavyweight base layers is that they can overheat if you overexert yourself which is why I always wear midweight base layers like this and just double them up if I have to. Another problem with base layers is that once they are on they are on and you have to take everything else off to change them so be sure they are the correct thickness before venturing off. The waffle zones in the weaving help both the heat retention and breathability as well as the stretchy support that makes these so easy to wear.


The SubZero Factor 1+ base layer system is very wearable on a daily basis due to its undeniably good fit and high performance. The thumb holes are a very nice touch but could possibly be located slightly lower down the sleeve for me personally. It is sufficiently warm with minimal over layers and not too warm with more layers on top. The super stretchy material provides a close fit without restricting your movements and really does wick moisture away without losing heat retention. The durability of the material is very good, it doesn’t ruck up your back and is unlikely to bobble over time.  I was very surprised to find myself liking this top so much but the quality really does show in the performance. I would go as far as saying this is one of the top 3 British base layers available today, pick one up using the link below.

Where to buy

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Features and specifications are taken from, thanks for reading this SubZero Factor 1 Plus Base Layer Review.

9 Total Score
Sub Zero Factor 1 Plus Base Layer Review

Sub Zero Factor 1 Plus Base Layer Review - Long Sleeve Seamless Thermal Insulation is super comfortable with lots of stretchiness and breathability.

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This article has been written and/or edited by Andrew N. 20+ years of hiking, mountaineering, and camping experience, with access to all the latest outdoor gear.

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